3

AT24C32C/64C [Preliminary]

5174B–SEEPR–12/06

Pin Description

SERIAL CLOCK (SCL): The SCL input is used to positive edge clock data into each

EEPROM device and negative edge clock data out of each device.

SERIAL DATA (SDA): The SDA pin is bidirectional for serial data transfer. This pin is

open-drain driven and may be wire-ORed with any number of other open-drain or open

collector devices.

DEVICE/ADDRESSES (A2, A1, A0): The A2, A1 and A0 pins are device address inputs

that are hard wired or left not connected for hardware compatibility with other AT24CXX

devices. When the pins are hardwired, as many as eight 32K/64K devices may be

addressed on a single bus system (device addressing is discussed in detail under the

Device Addressing section). If the pins are left floating, the A2, A1 and A0 pins will be

WRITE PROTECT (WP): The write protect input, when connected to GND, allows nor-

memory are inhibited. If the pin is left floating, the WP pin will be internally pulled down

>3pF, Atmel recommends connecting the pin to GND.

128/256 pages of 32 bytes each. Random word addressing requires a 12/13 bit data

word address.